| """ |
| phi.py |
| |
| Class definition for all LLMs derived from PhiForCausalLM. |
| """ |
|
|
| from typing import Optional, Type |
|
|
| import torch |
| from torch import nn as nn |
| from transformers import PhiForCausalLM |
| from transformers.models.phi.modeling_phi import PhiDecoderLayer |
|
|
| from prismatic.models.backbones.llm.base_llm import HFCausalLLMBackbone |
| from prismatic.models.backbones.llm.prompting import PhiPromptBuilder, PromptBuilder |
|
|
| |
| |
| PHI_MODELS = { |
| |
| "phi-2-3b": { |
| "llm_family": "phi", "llm_cls": PhiForCausalLM, "hf_hub_path": "microsoft/phi-2" |
| } |
| } |
| |
|
|
|
|
| class PhiLLMBackbone(HFCausalLLMBackbone): |
| def __init__( |
| self, |
| llm_backbone_id: str, |
| llm_max_length: int = 2048, |
| hf_token: Optional[str] = None, |
| inference_mode: bool = False, |
| use_flash_attention_2: bool = True, |
| ) -> None: |
| super().__init__( |
| llm_backbone_id, |
| llm_max_length=llm_max_length, |
| hf_token=hf_token, |
| inference_mode=inference_mode, |
| use_flash_attention_2=use_flash_attention_2, |
| **PHI_MODELS[llm_backbone_id], |
| ) |
|
|
| |
| self.tokenizer.add_special_tokens({"pad_token": "<|pad|>"}) |
| self.llm.config.pad_token_id = self.tokenizer.pad_token_id |
| self.llm.resize_token_embeddings(len(self.tokenizer), pad_to_multiple_of=64) |
|
|
| @property |
| def prompt_builder_fn(self) -> Type[PromptBuilder]: |
| if self.identifier.startswith("phi-2"): |
| return PhiPromptBuilder |
|
|
| raise ValueError(f"No PromptBuilder defined for LLM Backbone `{self.identifier}`") |
|
|
| @property |
| def transformer_layer_cls(self) -> Type[nn.Module]: |
| return PhiDecoderLayer |
|
|
| @property |
| def half_precision_dtype(self) -> torch.dtype: |
| return torch.bfloat16 |
|
|
